U.S. Pat. No. 2,630,516 discloses a curling iron for curling the eyelashes, the iron being provided externally with a sheath made of fibrous material, preferably chamois leather, with a view to retaining surplus mascara. In that patent, the heat serves to set the mascara.
EP 1 468 627 A1 describes a heating applicator for applying a viscous composition having a particular thermal profile. The composition is deposited on the applicator by immersing the applicator in a flask containing the composition and provided with a wiper member.
It is known from the publications WO 2006/043544, WO 2006/057438, WO 2006/057439, and WO 2006/057071 to apply a mascara composition to the eyelashes by means of a heated applicator device.
The devices disclosed in those publications are relatively complex and relate more to curling the eyelashes than to lengthening them.
In order to obtain a lengthened effect for the eyelashes, it is known to use a mascara composition that includes fibers. When the fibers are sufficiently rigid and visible, and when they are located at the end of the eyelashes, they can lengthen the eyelashes. The increase in length obtained by such a composition remains moderate, since it is relatively difficult to orientate fibers at the ends of the eyelashes.
As disclosed in WO 2006/037904 A1, another solution can consist in using a mascara composition that presents non-zero magnetic susceptibility, and in creating a magnetic field in the vicinity of the eyelash, thereby making it possible to act on the composition present on the eyelash so as to lengthen said eyelash by a magnetic attraction effect.
Another possibility consists in using a mascara composition that presents a thread-forming characteristic at ambient temperature, as disclosed in application EP 1 430 868 A1. Such a composition can however turn out to be relatively difficult to apply, since mastering the length of the threads formed at the ends of the eyelashes turns out to be tricky.
The Applicant has developed mascara compositions that present a thread-forming characteristic only when hot.